| Petronova Ltd | Potters Bar | 2025 |
| Petropavlovsk PLC | Milton Keynes | 2001 |
| Petrosaenz Limited | Beaconsfield | 2018 |
| Petroscan Ltd. | Hawarden | 2015 |
| Petrosea Energies UK Limited | Aberdeen | 2025 |
| Petrosedra Ltd | Cardiff | 2025 |
| Petrostrat Limited | Conwy | 2001 |
| Petrovannin UK Limited | Twemlow | 2002 |
| Petrovate Limited | Manchester | 2022 |
| Petrovision Energy Services Ltd | London | 2007 |
| Petrozone Well Technology Limited | Kingussie | 1991 |
| Petryx Ltd | Llanfairfechan | 2018 |
| Peudential Mining Limited | London | 2021 |
| PFR Subsea Ltd | Keith | 2017 |
| PGR Management Limited | Kingston Upon Thames | 2008 |
| PGS Exploration (UK) Limited | Weybridge | 1994 |
| PGS Geophysical (Angola) Ltd. | Weybridge | 1985 |
| Pgsubsea Ltd | Aberdeen | 2016 |
| Pharos Energy Israel Limited | London | 2020 |
| Pharos Energy PLC | London | 1997 |
| Pharos Marine Automatic Power Limited | Hampton | 2008 |
| Pheadra Engineering Ltd | Ellon | 2007 |
| Phigold UK PLC | London | 2016 |
| Phil Beaumont Ltd | Comrie | 2019 |
| Philippine Gold Limited | Leytonstone | 1960 |
| Phin OIL & GAS Electrical Solutions Limited | Dundee | 2019 |
| Phoenix Arises Ltd | Keighley | 2013 |
| Phoenix Decom Ltd | Aberdeen | 2021 |
| Phoenix Global Resources Limited | London | 2004 |
| Phoenix OIL & GAS Limited | London | 2009 |
| Phoenix RDS Ltd | Huntly | 2016 |
| Phoenix Resources Ltd | Surbiton | 2006 |
| Phoka's Bussiness Management Consultancy Ltd | Weston-Super-Mare | 2023 |
| Phuel OIL Tools Limited | Aberdeen | 2004 |
| Physe Limited | Newport | 2002 |
| PI Albany Petroleum Ltd | Croydon | 2021 |
| PI Engineers Limited | Aberdeen | 2019 |
| Pierce Production Company Limited | London | 1998 |
| Pilling Geoconsultants Limited | Aberdeenshire | 2005 |
| PIMLICO24 Ltd | Nottingham | 2013 |
| Pinden Limited | Orpington | 2004 |
| Pinnacle Energy Limited | Stroud | 1999 |
| Pinnacle Inspection Services Limited | Kirkcaldy | 2013 |
| Pinnacle Race Gear Ltd | Dundee | 2009 |
| Pioneering Energy Solutions Ltd | Canterbury | 2023 |
| Pipe Maintenance International Limited | Darlington | 2013 |
| Pipeline Access Ltd | Blackpool | 2019 |
| Pipeline Compliance & Consulting Ltd | Sheffield | 2017 |
| Pipemark UK Ltd | Beauly | 2008 |
| Pipes R US Limited | Brighton | 2014 |
| Piran Mining UK Limited | Falmouth | 2017 |
| Pisara Ltd | Aberdeen | 2025 |
| PIT Aggregates Ltd | Retford | 2025 |
| Pitgaveny Trading Company Limited | Elgin | 1979 |
| Pitkin Petroleum Limited | London | 2005 |
| PJ Mining Limited | Worthing | 2016 |
| PJA ROV Services Ltd | Elgin | 2025 |
| PJB Inspection Ltd | Aberdeen | 2026 |
| PJB Offshore Limited | Stockton-On-Tees | 2020 |
| PJH Metallurgical Consultancy Ltd | London | 2018 |
| PJM Inspection Services Limited | Grays | 2014 |
| PJR Plant Ltd | Doncaster | 2014 |
| PJT NDT Inspections & Rope Access Limited | Fleetwood | 2013 |
| PJW Access Limited | Blackpool | 2019 |
| PJW Lifting Ltd | Blackpool | 2020 |
| PKB Engineering Solutions Ltd | Newcastle Upon Tyne | 2021 |
| PKP Exploration 2 Limited | London | 2006 |
| Plainview Ltd | Montrose | 2014 |
| Planetary AI Limited | Golspie | 2020 |
| Plant for People Mining Ltd | Swindon | 2025 |
| Platts & Projects International Company Ltd | Erith | 2024 |
| Pleacairn Offshore Limited | Dumfries | 2021 |
| PLF Consulting Limited | Henley-On-Thames | 2002 |
| Plinian Capital Limited | Richmond Upon Thames | 2009 |
| Plisa Ltd | Liverpool | 2022 |
| Pmdr Limited | 175 West George Street | 2010 |
| PMI Offshore Ltd | Cambuslang | 2018 |
| Pmoll-Seismic Limited | Alford | 2017 |
| PMR Offshore Ltd | Seaford | 2018 |
| PMW Quarries Limited | Huddersfield | 2009 |
| Pod-Tec Limited | Peterhead | 2024 |
| Point Five (Well Services) Limited | Edinburgh | 1998 |
| Poland Biology Amino Acid Chemical Share Co., Ltd | Cambridge | 2025 |
| Polar Well Services Ltd | Montrose | 2023 |
| Polish Amino Acid Fertilizer and Chemical Stock Co., Ltd | Beckenham | 2023 |
| Polstox Limited | London | 2023 |
| Pomerite Limited | Basingstoke | 2021 |
| Porcelain Flooring Direct Ltd | Preston | 2019 |
| Porphyrogenitus Limited | Crowthorne | 1987 |
| Portfutures International Corridors Limited | Northampton | 2023 |
| Portland Stone Firms Limited | Portland | 1994 |
| Portland Stone Mines Limited | Weymouth | 2021 |
| Poseidon Energy Services Limited | Great Yarmouth | 2025 |
| Poseidon Engineering Solutions Limited | Balgownie Road, Bridge Of Don | 2016 |
| Poseidon Process Services Limited | Lowestoft | 2022 |
| Powa Consultants Limited | East Huntspill | 1998 |
| Power Motors Technology Ltd | London | 2018 |
| Power Resources International Ltd | Brighton | 2020 |
| Power Sales Limited | Solihull | 2015 |
| Power Trace GEO Limited | Woking | 2018 |